Mandrel for use in machines for making artificial straws and other tubes



C. CASEY MANDREL FOR USE IN MACHINES FOR MAKING ARTIFICIAL STRAWS AND OTHER TUBES Dec. 3, 1929.

Filed Feb. 18, 1929 2 Sheets-Sheet 1 Dec. 3, 1929. c. CASEY 1,738,035

MANDREL FOR USE IN MACHINES FOR MAKING ARTIFICIAL STRAWS AND OTHER TUBES Filed Feb. 18, 1929 2 Sheets-Sheet 2 wmw M Patented Dec. 3, 1929 UNITED STATES PATENT OFFICE CARL CASEY, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO STONE STRAW CORPORATION, OF WASHINGTON, DISTRICT OF COLUMBIA, A CORPORATION OF DELAWARE MANDBEL FOR USE IN MACHINES FOR MAKING ARTIFICIAL STRAWS AND OTHER TUBES Application filed February 18, 1929. Serial No. 340,894.

This invention relates to a mandrel for use in artificial straw making machines of the type wherein a plurality of paper strips are spirally wound on a fixed mandrel by an endless belt which is wrapped therearound a number of times and which engages the paper strips to feed and wind them into a continuous tube, the tube subsequently being cut to convenient lengths. More specifically, my invention comprises a mandrel, the stem of which is initially bent in a direction away from that of the travel of the belt whereby, in operation of the straw making machine, the mandrel stem will tend to straighten, such tendency causing it to assume a compound curvature thereby to facilitate Wrapping of the paper tube and its continuous removal from the mandrel without tearing or mutilation; all as will be more fully described and claimed hereinafter.

It is an object of my invention to provide a mandrel for artificial straw making ma chines which will permit of the continuous formation of a paper tube by spiral winding and the continuous and free withdrawal of such tube from the mandrel without danger of its freezing or sticking thereto with resultant mutilation.

Another object is to provide a mandrel,

the stem of which is curved, whereby a continuous paper tube can be formed thereon and removed therefrom freely and continuously with minimum waste from tearing or other mutilation.

A further object is to minimize the paper waste resulting from the manufacture of artificial straws, by the use of a curved man drel. which permits the free removal of a continuously therefrom.

Other and further objects will be apparent from the following description and drawing, in which Figure 1 is a plan view of a machine provided with a mandrel in accordance with this invention, the compound curvature of the mandrel as shown being exaggerated for clearness of illustration.

Figure 2 is a plan view of a mandrel beaEore use.

formed paper tube or straw The mandrel comprising this invention is adapted for use with machines of the type described in U. S. patent to Albert A. Carper, N 0. 1,252,235, wherein an endless belt or band passes around a fixed mandrel and serves to feed a plurality of narrow paper strips and at the same t me to form these strips into a continuous multi-ply tube. A detailed descrlption of the machine disclosed in the aforesaid patent will not be necessary for an understanding of the present invention, but, the machine comprises a bed 10 on one end of which is mounted the straw spinnlng mechanism and on the other end a cut oil mechanism 11 for cutting a continuously formed. paper tube into convenient lengths. A bolster 12 extends diagonally across the bed 10 and forms the support for the entire straw-winding or spinning mechanism, with the exception of the mandrel 13 which is clamped in the bracket 14 bolted to the bed 10, and angularly adjustable thereon.

Wheels 15 and 16 are vertically journalled in the crossheads 17, 17, one being driven by gearing, not shown, and serving to drive the other by means of a belt 18 which passes around both wheels. The tension of the belt may be varied by adjusting the cross-heads to ward and away from each other as by means of a screw shaft 19, provided with a handgrip 20, and journalled in bearings 21, 21, on the bolster. The screw shaft has collars 22, 22 abutting the bolster bearings 21, 21 to hold it against endwise movement, and its a;

l as

mounted the straw cut-off mechanism and a straw guide 28, in this instance shown as a tubular member with a flaring, bell-shaped mouth 29.

A plurality of continuouspaper-strips 30 and 31 are fed to the machine under clamps 32, attached to the glue pot, which frictionaL' 1y engage the strips to maintain them taut. The strip 30 contacts the glue wheel 25, which is rotated in a bath of glue, while strip. 31 passes to one side of the wheel and is fed directly to the mandrel without being coated static charge, and

'on the mandrel there is a tendency for the tube to stick to the mandrel stem, so that it .is torn when excessive pull is exerted by the belt to remove it. Also, because of static electricity generated by friction of the paper as it rubs against the tensioning means and mandrel, this tendency of the aper to stick tothe mandrel is increased. arious expedients have been resorted to, to eliminate these disadvantages, suchas grounding the machine to dischar the constantly forming ricating the mandrel surface to permit the paper to slip more easily thereover, but these, although to some extent satisfactory for'their purposes, did not prevent tearing ofthe paper as it was withdrawn from the mandrel in tubular form and wastage of paper was considerable.

*It has been found that entirely satisfactory results can be obtained by using a mandrel inade in accordance with this invention, with minimum waste of paper. and: greatly mcreased efiicienc' in the operation of the machines and pro uction of straws.

As is shown in Figure 2 of the drawing, the

. improvedmandrel comprises a stem 13 and'a socket 33, the stem being bent so that its end extends to one side of the centerline a. The socket portion 33 is clamped in bracket 14 and the bracket is adjusted on the bed plate 10 so that the center line a which extends along the axis of the mandrel socket and through the pivotal axis of. the bracket passes to one side of the straw guide 28.

' In use, the belt 18 which is wrapped around the-mandrel stem exerts a constant pull, in one direction, as is indicated by the arrow in Figure 1 of the drawing. Such pull on the mandrel stem causes it to assume a compound curvature, as is shown somewhat exaggerated in Figures 1 and 3, wherein the stem acquires a reverse bend as at-34, thus extending for a portion of its length below center line a and then crossing such line and terminating above it.

The practical result of the use of my curved mandrel is that the tube which is formed thereon may be freely and continuously removed without binding or freezing to the mandrel, whereas with straight mandrels in straw machines tearing and waste of paper is unavoidable. The precise theory which would account for the superior results obtained by my bent mandrel is not known, but, after years of experimentation, I believe these results are due to the formation of a pocket of air which isentrapped beneath the paper strip 31, as is indicated at 35 in Figure 3 of the drawing. This pocket of entrapped air largely destroys actual physical contact between the pa r and mandrel, and serves not only to cushion the paper tube but also acts as a dielectric, preventing the formation of electrostatic charges which would interfere with the free withdrawal of the tube from the mandrel.

What I claim as my invention is:

1. In machines for spirally wrapping paper tubes a mandrel having a curved stem.

2. A mandrel for tube making machines comprising a socket portion and a stem, the said stem being bent at an angle to the axis of the socket portion.

3. In tube making machines a mandrel having a socket portion and a stem bent at an angle to the axis thereof, a supply of tube material, a driven belt for feeding the tube material and spirally winding it on the mandrel, the said mandrel being mounted in the machine with its'bent stem inclined away 4. A mandrel for tube machinescomprising a stem of .compound curvature.

5. A mandrel for tube machines comprismg a socket portion and a stem, the said stem being curved to extend for a portion of its len h to one side of the axial line of the soc et and for the remainder of its length on the other side of said line.

'6. A reversely curved mandrel for tube machines.

7 A mandrel for tube machines having a curved stem and a reversely curved portion formed in said curved stem.

8. A mandrel for tube machineshaving a stem of generally S-shaped curvature.

In testimony whereof I afiix my si ature.

. CARL CA EY. 

